A/C winter wonderland

[Handruin]

I thought I'd share a small experience I had after I came home from work this afternoon. These past two weeks have been a mess of humid rainy weather. Because of this I've left my A/C on for a long time.

Today I come in the door, and I'm surprised at how warm my apartment is. Normally is about 80 degrees F in my computer room during the summer with the A/C on. Today I come in my room and my thermometer reads 84 degrees...

So I decide to kick up the A/C figuring it has been on low and maybe it was warmer than I thought outside...however I notice no air is coming out if it. So, I peek into the vent and I'm amazed at what I see...solid white.

I'll let the pictures describe the rest...


Frozen 1
Frozen 2
Frozen 3

 

[flagreen]

A dirty filter will cause that. I noticed the fan is covered in dust. It can also be caused by the drain cloging or insufficient freon. But based on the dust in the fan, I'd say that's the most likely problem.

 

[Groltz]

Let me guess, Doug....That AC unit isn't yours but came with the apartment?

 

[Handruin]

Let me guess, Doug....That AC unit isn't yours but came with the apartment?

Correct! (and it's a piece of shit)

After the freeze-over, I pulled out the vacuum and cleaned everthing I could. Before I cleaned the unit, I used a hair dryer (on low) to melt the ice. (it took about 20 minutes) The coils are still very cold so I turned the A/C unit to fan to allow the coils to dry off for a bit. This thing has been running for about 1 1/2 to 2 weeks straight.

I cleaned the dust about this time last year, and figuring that I don't use the A/C in the winter...it wouldn't be that dirty...but it was.

 

[blakerwry]

as flagreen said, lack of freon can cuase that problem.. happen ed to us, we had a very small freon leak and over time we would get the exact same ice buildup on the inside and outside pipes in our central air.

we had to replace the condensor.

 

[blakerwry]

i still have the old one if anybody wants to setup an extreme heat exchanger for a water cooling setup....

 

[Mercutio]

Shortly after I moved into my original apartment (before Amy moved in with me to begin with), my apartment-provided AC caught fire the first time I switched it on (fortunately, while the apartment was mostly empty).

 

[jtr1962]

Ice on the cold side fins can happen even with a normally functioning A/C and a clean filter. When I bought my bedroom AC in 1994 one of the first things I did was to change the range of the thermostat. Most mechanical thermostats have a one on two screws inside for this. One controls the temperature range, the other the hysteresis(i.e the unit shuts off a few degrees lower than it kicks on to prevent constant compressor cycling). Anyway, the stock range was approximately 64°F to 90°F. I reasoned that anything above 80°F is useless space on the dial since I would always want the room cooler so I readjusted to range downwards about 10° so that it was ~53°F to 80°F. In the course of testing it I noticed that sometimes the unit would stop cooling effectively when the room got under about 55°F. This was due to ice buildup. The cold side fins are roughly 25°F less than room temperature. Once room temp gets under the mid fifties, the fins get under freezing temperature and you have ice buidup. Of course this isn't that big of an issue because most of the time it's too hot out for the A/C to even be able to get the room that cold(it's a 5800 BTU unit in a 10x11 room). Also,while I like the room cool I generally don't keep it in the fifties unless I've been out gardening in the heat all day and have ended up with heat exhaustion. Those few times that happens I'd probably keep the room in the thirties if I had an A/C with the capability. Anyway, this is the reason why A/Cs sometimes get ice, and why your fridge needs to defrost periodically. Blocked or dirty filters can also let the fins get under freezing. In fact, in a test the fins on my unit get down to -10°F if I cover them completely with an old pillow.